CURRENT PICKUP Russian patent published in 2002 - IPC

FIELD: electric measurement technology, measurement of alternating currents in power meters of commercial frequency. SUBSTANCE: technical result of proposal lies in increased accuracy of current measurements thanks to compensation for growth of voltage across shunt caused by rise of ohmic resistance during its heating and compensation for parasitic inductive resistance of shunt. Wire resistor is placed between current input of shunt and inverting input of operational amplifier. Shunt of current pickup comes in the form of n insulated U-shaped plates of same dimensions positioned in parallel. Inputs and outputs of all plates are correspondingly current input and output of shunt and are so interconnected that directions of currents flowing through adjacent plates are mutually opposite. Wire resistor is manufactured in the form of winding on U-shaped plates orthogonal to direction of currents in U-shaped plates. Materials used to manufacture wire resistor and U-shaped plates should have same temperature coefficient of resistance. EFFECT: increased accuracy of current measurement. 2 dwg